In microprocessor control systems as used in motor vehicles for the control of engine operations and control of the engine itself, many of the sensors used generate an analog output signal. Since most microprocessors are digital devices, the analog signals must be converted to digital signals. The device for doing such conversion is an analog to digital, A/D, converter.
One such microprocessor control system is described in U.S. Pat. No. 4,556,943 issued to Pauwels et al. on Dec. 3, 1985 entitled "Multiprocessing Microprocessor Based Engine Control System for an Internal Combustion Engine" and assigned to a common assignee. In that system the various sensors are connected to an A/D converter and its output is connected to one of the microprocessors. In that system the sensor signals are converted to eight bit digital words for use by the microprocessor and the resulting resolution is only eight bits.
It is a principal advantage of the present system to increase the resolution of digital words by creating an additional bit of Least Significiant Bit (LSB) information. It is a further advantage to create an additional bit of least significant bit (LSB) resolution upon demand of the microprocessor.